It is prior art to prepare beverages such as coffee, tea or hot chocolate from capsules containing a predetermined serving of a substance to be extracted. The capsule format has the advantage of facilitating the operations of preparing the drink, ensuring clean preparation without leaving visible traces of the substance, and controlling the reproducibility and quality of the prepared product.
The principle of extracting from a capsule generally consists in (i) enclosing the capsule in a pressure-resistant chamber, (ii) piercing one of the faces of the capsule, (iii) introducing a quantity of hot water into the capsule to create a closed pressurized environment to produce the liquid coffee or other extract, (iv) releasing the liquid extract through the opposite face of the capsule, and (v) collecting the extract in a container of suitable capacity, such as a cup.
The problem of loading the capsule into the extraction system and removing it therefrom has already been the subject of a number of patent publications.
Patent application EP 1 090 574 A1 relates to an extraction device comprising a pair of jaws with a fixed jaw part and a movable jaw part, the latter being articulated to and moved over the fixed part, and a closing lever mechanism with a plurality of arms is associated therewith to close the movable part over the fixed part.
In published document WO 01/30218 A1, the principle is similar but a mechanism for ejecting the capsule is additionally provided, associated with a pulling arm of the movable jaw so as to detach the capsule from the bottom of the extraction chamber when the jaw is reopened.
Based on these principles, it is obvious that a closure device with two parts, one fixed and one movable, optionally associated with an ejector, is known. However, these devices are essentially manual closure devices and are not very suitable for automating the closure function. It should also be noted that because of the movement of the axes of articulation, such systems must be designed and assembled with precision so as to avoid clearances and problems in fitting the parts together.
Patent application WO 95/17121 relates to a device comprising an assembly formed of a fixed piston and a movable cylindrical body, the assembly being placed facing a boiler. Between the boiler, on the one hand, and the fixed piston and cylindrical body, on the other hand, is a zone containing the means for receiving, holding in position and ejecting the packages. The holding means and the reception means are different means. The former are not entirely retractable and are placed directly between the boiler and the cylindrical body to hold the side edges of the package, and the latter are retractable and placed on one side of the cylindrical body to simply stop the package in opposition to the force of gravity. Such a device is complex since it uses various parts to simultaneously hold and correctly centre the capsule (or package) in position in the extraction chamber. This involves several separate mechanisms for moving the means in order to close the extraction system. The offset position of the holding means can also give rise to problems of jamming or premature wear. Furthermore, such a device is also relatively bulky because of the peripheral position of the holding means and of the boiler.
Patent application WO 98/47418 relates to a method for converting an espresso machine operating in vertical extraction with pre-measured tablets used in a horizontal plane into an espresso machine operating in horizontal extraction with pre-measured tablets which can be used in a vertical plane. The machine has reception and ejection means consisting of a single retractable component which can be moved underneath the extraction member using an electromechanical maneuvering means that is separate from the means for actuating the extraction member.
Patent application WO 00/38558 relates to an extraction chamber for an automatic machine composed of two movable parts in a horizontal plane, one of which is supplied with hot water, the other having a filter, the two parts being mounted so as to pivot vertically one opposite the other along their transverse axis.
Patent application WO 00/44868 relates to an extraction device comprising an extraction chamber composed of two parts that can move horizontally so that they can be moved towards or away from each other, the parts being mounted on an eccentric shaft that can transmit to them pivoting movements in opposite directions, the device comprising a pivot link braked between each eccentric shaft and each moving part so as to combine a horizontal movement and a pivoting movement for linking together the steps of opening and closing the extraction chamber.